The present invention concerns chairs with adjustable lumbar supports, and more particularly concerns a chair having a vertically adjustable lumbar support apparatus.
Adequate lumbar support is very important to people spending long hours sitting in chairs. However, people have different body shapes and have different preferences. For these reasons, it is not easy to design an adjustable lumbar support that meets the needs of most people, yet that is not unacceptably expensive, complex, and/or difficult to assemble. Further, people require different amounts of lumbar support throughout a workday and different people may use a particular chair. Many different people may use a chair over the life of the chair and it is not always possible to train them on how to best adjust the chair. For this reason, it is desirable to provide an adjustable lumbar support mechanism that is easily adjustable, intuitively adjustable, as well as smoothly functional during adjustment. Another problem is that adjustable lumbar supports must fit within the aesthetics and decor of a particular style of chair. Specifically, many chairs have stylized backs with non-uniform edges, covered front and rear surfaces, and refined edge trimmings, which features increase the complexity of a lumbar support mechanism when it is hidden inside the back.
Recently, a chair was conceived having a very flexible, highly compliant back that flexes in a manner providing excellent postural support, but that is highly sympathetic to the manner in which a seated user flexes their spine, especially in a lumbar area. (The chair is disclosed in application Ser. No. 08/957,473, filed Oct. 24, 1997, by inventors Glenn A. Knoblock et al., entitled Chair Including Novel Back Construction, the entire contents of which are incorporated herein by reference in its entirety.) In this chair, the adjustability of the lumbar support is made more difficult, since the back shell is so flexible in the lumbar area that the lumbar area of the back shell itself changes shape during adjustment of the vertical lumbar support and during flexure of a spine and back of a seated adult user. In order for the lumbar support mechanism to function properly, it must be held against the lumbar area of the back shell during adjustment. This raises several competing functional requirements. When taken in combination with the other functional and aesthetic requirements of this chair, the conflicting design requirements are significant. In addition, it is preferred that this adjustable lumbar support mechanism be retrofittable.
Accordingly, a chair having a footrest solving the aforementioned problems and having the aforementioned advantages is desired.